const Drag = {
  install(Vue) {
    Vue.directive('drag', (el, binding, vnode, oldVnode) => {
      // inserted (el, binding, vnode, oldVnode) {
      Vue.nextTick(() => {
        // const isThemeModal = el.classList.contains('grid-theme')
        // const dialogHeaderEl = isThemeModal ? el.querySelector('.ant-tabs-bar') : document.querySelector('.ant-modal-header')
        // const dragDom = isThemeModal ? el.querySelector('.ant-modal') : document.querySelector('.ant-modal')
        const dialogHeaderEl = el.querySelector('.ant-modal-header')
        const dragDom = el.querySelector('.ant-modal')
        if (!dialogHeaderEl || !dragDom) {
          return false
        }
        // dialogHeaderEl.style.cursor = 'move'
        dialogHeaderEl.style.cssText += ';cursor:move;'
        // dragDom.style.cssText += ';top:0px;'

        // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
        const sty = (function() {
          if (window.document.currentStyle) {
            return (dom, attr) => dom.currentStyle[attr]
          } else {
            return (dom, attr) => getComputedStyle(dom, false)[attr]
          }
        })()

        dialogHeaderEl.onmousedown = (e) => {
          // 鼠标按下，计算当前元素距离可视区的距离
          const disX = e.clientX - dialogHeaderEl.offsetLeft
          const disY = e.clientY - dialogHeaderEl.offsetTop

          const screenWidth = document.body.clientWidth // body当前宽度
          const screenHeight = document.documentElement.clientHeight // 可见区域高度(应为body高度，可某些环境下无法获取)

          const dragDomWidth = dragDom.offsetWidth // 对话框宽度
          const dragDomheight = dragDom.offsetHeight // 对话框高度

          const minDragDomLeft = dragDom.offsetLeft
          const maxDragDomLeft = screenWidth - dragDom.offsetLeft - dragDomWidth // - (isThemeModal ? 10 : 0)

          const minDragDomTop = dragDom.offsetTop
          let maxDragDomTop = screenHeight - dragDom.offsetTop - dragDomheight // - (isThemeModal ? 10 : 0)
          maxDragDomTop = maxDragDomTop > 0 ? maxDragDomTop : dragDom.offsetTop
          // 获取到的值带px 正则匹配替换
          let styL = sty(dragDom, 'left')
          let styT = sty(dragDom, 'top')

          // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
          if (styL.includes('%')) {
            // eslint-disable-next-line no-useless-escape
            styL = +document.body.clientWidth * (+styL.replace(/\%/g, '') / 100)
            // eslint-disable-next-line no-useless-escape
            styT = +document.body.clientHeight * (+styT.replace(/\%/g, '') / 100)
          } else {
            styL = +styL.replace(/\px/g, '')
            styT = +styT.replace(/\px/g, '')
          }

          document.onmousemove = function(e) {
            // 通过事件委托，计算移动的距离
            let left = e.clientX - disX
            let top = e.clientY - disY

            // 边界处理
            if (-(left) > minDragDomLeft) {
              left = -(minDragDomLeft)
            } else if (left > maxDragDomLeft) {
              left = maxDragDomLeft
            }

            if (-(top) > minDragDomTop) {
              top = -(minDragDomTop)
            } else if (top > maxDragDomTop) {
              top = maxDragDomTop
            }
            // 移动当前元素
            dragDom.style.cssText += `;left:${left + styL}px;top:${top + styT}px;`
          }

          document.onmouseup = function(e) {
            document.onmousemove = null
            document.onmouseup = null
          }
        }
      })
    })
  }
}
export default Drag
